Position lifetime amd coincidence doppler broadening studies of graphene oxide - polyaniline nanocomposite

Abstract

In this work, we report about the results of a detailed investigation comprising of measurements of positron lifetimes and coincidence Doppler broadening of the electron positron annihilation gamma ray spectra on graphene oxide – polyaniline nanocomposite samples prepared with different ratios of weight and at different temperatures. The two experimental techniques are capable of providing information respectively on the elec- tron density and momentum distribution at the specific sites of annihilation. This makes them effective in identifying the different types of defects present in the composite matrix. The magnitudes of the positron lifetimes were commensurate with the expectation of very large size defects in the form of vacancy clusters within the atomic composition of the composite material. The average defect size apparently reduced when the relative abundance of polyaniline increased that led to increased reduction of graphene oxide to graphene. The reduction also resulted in the shrinkage of the graphene oxide matrix and the free volume thereby released added to the overall defect concentration. The variation of the positron lifetime and its intensity with the temperature of synthesis suggested an optimum temperature suitable for the process. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/20625